Fabrics obtained by weaving warps and wefts have conventionally been used widely as an industrial fabric. They are, for example, used in various fields including papermaking fabrics, conveyor belts and filter cloths and are required to have fabric properties suited for the intended use or using environments. Of such fabrics, a papermaking fabric used in a papermaking step for removing water from raw materials by making use of the network of the fabric must satisfy a severe demand.
For example, there is a demand for the development of fabrics which do not transfer a wire mark of the fabric and therefore have excellent surface property, the ones which have enough hydration property for sufficiently and uniformly hydrating excess water contained in the material and enough rigidity or wear resistance to be usable desirably even under severe environments, or the ones which are capable of maintaining conditions necessary for making good paper for a prolonged period of time.
In addition, fiber supporting property, improvement in a paper making yield, dimensional stability and running stability are demanded.
In recent years, owing to the speed-up of a paper making machine, requirements for papermaking fabrics become severe further.
Since most of the demands for industrial fabrics and solutions thereof can be understood if papermaking fabrics on which the most severe demand is imposed among industrial fabrics is described, the papermaking fabric will hereinafter be described as a representative example.
Recently, particularly excellent hydration property and surface smoothness have been required due to the high speed operation of a machine for fabric. Although the required hydration property varies in accordance with the machine and the product papers, the uniform hydration property is commonly required for all the product papers.
In addition, the sufficient and uniform hydration property has become important, since old papers has been increasingly used in recent years, so that the sufficient hydration is not carried out due to the much fine fibers contained therein.
Further, generally, the fabric is formed by intermitting warps each arranged to be straight, so that the distance between wefts and warps is kept constant if the woven structure is changed. Accordingly, another technical problem of a generation of wire mark has risen due to the straight space formed between the warps.
In order to solve above technical problems, the fabric which adopts so-called a lateral structure in which the warps and the wefts are woven with each other in a meandering manner. For example, in Patent Publication 1, a two-layer fabric for making papers in which such a lateral structure is formed on an upper surface side warps is disclosed. In Patent Publication 2, an industrial two-layer fabric in which such a lateral structure is formed on an upper surface side wefts is disclosed. In Patent Publication 3, a single layer fabric for making papers in which a lateral crimp is formed on warps is disclosed.
However, in the two-layer fabric for making papers in Patent Publication 1, a technical problem related to rigidity, etc. has risen due to use of the wefts as warp binding yarns.
In addition, in the industrial two-layer fabric in Patent Publication 2, it is technically difficult to increase the number of the shooting counts of the wefts, due to the fact that the fabric is formed by meandering the wefts relative to the running direction thereof to a higher degree, as compared to the normal wefts.
Further, in the single layer fabric for making papers in Patent Publication 3, the surface smoothness and the wear resistance are inferior to the two-layer fabric.
Patent Publication 1: Japanese Patent No. 4584398
Patent Publication 2: Japanese Patent Laid-open Publication 2010-126848
Patent Publication 3: Japanese Patent No. 3530623